1. Field of the Invention
This invention relates to gallium arsenide (GaAs) high density logic circuitry. More particularly, this invention relates to GaAs circuitry which can be implemented in the form of a novel high density integrated circuit to provide combinational gating with improved speed power product.
2. Description of the Prior Art
In addition to the above-mentioned related cases which show differential amplifiers employed to drive one family of logic from another family or logic, simple GaAs gate structures are known which will perform such functions as AND, NAND, OR, NOR and EXCLUSIVE OR functions.
Numerous different types of transistor logic are commercially available in the form of integrated circuits.
Manufacturers of semiconductor devices often produce a complete series of such integrated circuits which are referred to as families of devices and which are completely compatible with each other. Such families of integrated circuits will accept the input from a similar family of logic and will produce an output signal which is capable of driving a similar family of logic.
It is not uncommon for logic designers of equipment, such as high speed computers, to adapt in the same computer more than one family of semiconductor devices. When the input voltage levels and output voltage levels of signals from the different families of devices are not matched, they are referred to as being incompatible and require some form of signal conversion to assure that the logic signals are properly sensed and processed. Typically, the power supply levels may be different, the logic voltage swings may be different or the signals may require reshaping, amplification and/or attenuation for producing proper threshold voltage levels.
The above problems are understood by those skilled in the art. Commercially available translators and converters are sold by semiconductor manufacturers to interface incompatible logic signals between some of the different families of integrated circuit devices. The two above-mentioned related applications serve the purpose of interfacing emitter coupled logic (ECL) voltage levels with GaAs logic voltage levels and also interface GaAs logic voltage levels with ECL logic voltage levels.
It would be desirable to provide a high speed-low power, high density GaAs basic logic circuit adapted for implementation as an integrated circuit and to provide therewith all of the necessary translation and conversion on the same circuit without the requirement of additional logic components which would slow down the logic signals being processed as well as take up additional area on the integrated circuit.
It would also be extremely desirable if the translation or conversion of the logic signals was performed in the logic circuitry without the requirement for additional conversion circuitry on the GaAs integrated circuit chip. It would be desirable that the translation or conversion of the logic signals be performed simultaneously with the performance of the gating logic of the basic logic circuit so as to speed up the time required for processing such signals. It would be desirable that the GaAs logic circuitry be implemented in a form which is faster and requires less power than conventional circuits.